Chloroflexus aurantiacus has 30S ribosomal subunits of the eubacterial type.

Ribosomal subunits from Chloroflexus aurantiacus were isolated and examined by sucrose gradient sedimentation, gel electrophoresis, and electron microscopy. The 30S subunits had all the characteristic structural features of other eubacterial 30S subunits. The data support the proposal that the absence of the archaebacterial bill is a valid phylogenetic marker of the eubacterial lineage.